Advances in wireless power transfer technologies have enabled popularization of electronic devices using wireless charging. In line with this trend, international standards for wireless power transfer have been developed by industry organizations, such as wireless power consortium (WPC), power matters alliance (PMA), and alliance for wireless power (A4WP).
Meanwhile, the WPC, PMA and A4WP standards for wireless power transfer may require different frequencies or duty cycles for wireless charging. In particular, unlike the WPC or PMA standard allowing the frequency and duty cycle to vary, the A4WP standard based on high-frequency resonance may require fixed-frequency output using a solid crystal structure owing to the narrow tolerance. This may make it difficult to achieve compatibility between standards for wireless charging devices.
In addition, as wireless power transfer techniques may be vulnerable to electromagnetic interference (EMI), it is necessary for an electronic device to use a scheme that is least vulnerable to EMI for stable wireless charging.
The above information is presented as background information only to assist with an understanding of the present disclosure. No determination has been made, and no assertion is made, as to whether any of the above might be applicable as prior art with regard to the present disclosure.